积雪草多糖的提取及其抗氧化性能研究

生物工程论文编号:SW047  论文字数:8788,页数:23

目 录
中文摘要 I
英文摘要 II
目 录 III
1 绪 论 1
1.1 积雪草概述 1
1.2 积雪草研究现状 1
1.3 多糖概述 2
1.4 多糖研究现状 2
1.5 本章小结 3
2 实验部分 4
2.1 材料与设备 4
2.2 实验主要试剂 5
2.3 实验方法 6
2.4 本章小结 9
3 结果和讨论 10
3.1 积雪草粗多糖提取 10
3.2 粗糖蛋白中蛋白质含量的测定 10
3.3 脱蛋白处理 11
3.4 脱蛋白效果复测 11
3.5 粗多糖中己糖含量的测定 11
3.6  β-胡萝卜素漂白法测定积雪草多糖抗脂质过氧化活性 13
3.7  单糖组成分析 13
4 总结与展望 16
致 谢 17
参考文献 18

摘要： 本实验以积雪草为原料，用水煮醇沉法提取了积雪草粗糖蛋白，测得其提取率为6.5%；用考马斯亮蓝G-250法对提取的积雪草粗糖蛋白的蛋白质含量作了测定，结果为3.45%；得到的粗糖蛋白用酶+Sevag法脱蛋白，处理了8次后无明显的蛋白层；考马斯亮蓝G-250法复测脱蛋白后的积雪草多糖，测得所剩蛋白含量极微，说明脱蛋白效果显著；脱蛋白后得到的积雪草多糖用苯酚-硫酸法测糖含量，测得粗多糖中己糖含量为57.9%。
 采用β-胡萝卜素漂白法测定积雪草多糖抗脂质过氧化活性，结果显示积雪草多糖在剂量为10~20 mg/ml范围时，具有较强的抗氧化活性。在同等剂量5 mg/ml下强于阳性对照Vc，5 mg/ml的积雪草多糖的抑制率为54.3%，而阳性对照Vc(5 mg/ml)的抑制率为38 %。
    对积雪草粗多糖的单糖组成进行了气相色谱检测，结果显示其单糖组分中含有麦芽糖和D-木糖。
关键词：积雪草；多糖；提取；抗氧化活性

Study on the extraction, purification and antioxidant activity of polysaccharide in Centella asiatica
Abstract: In this study, the Centella asiatica was extracted with water and Centella asiatica crude polysaccharide protein was obtained with a productivity of 6.5%. The protein content of the Centella asiatica crude polysaccharide measured with Coomassie brilliant blue G-250 method was 3.45%. The crude polysaccharide was deproteined with enzyme and Sevag, after handling 8 times there was no obvious protein layer left. Took the Coomassie brilliant blue G-250 method again , and result showed that there was little protein contained in the crude polysaccharide, the effect of deproteinning was good. The polysaccharide content of the deproteined crude polysaccharide was measured with phenol and sulfuric acid, hexose had a content of 57.9%.
   The antioxidant activity of crude polysaccharides was also studied by β-carotene bleaching assay, which showed that Centella asiatica crude polysaccharides have distinct antioxidant capacity compared with vitamin C as the positive control.
    We us the GC method to test the monosaccharide composition of Centella asiatica polysaccharides, and the result showed that maltose and D-xylose are two compositions of crude polysaccharides.
Key Words：Centella asiatica; Polysaccharides; Extraction; Antioxidant activity